Improvement in steam boilers and superheaters



s. N. CARVAL HO. STEAM-BOILER AND SUPERHEATER. No. 192,678, y Patented July 3,1877.

ogb o o. 00 o o mmron M ATTORNEYS.

WITNESSES:

N.PETERS. PHOTO-LITHOGRAPHER, WASHINGTON. n.6,

U'NITED STATES PATENT OFFICE.

SOLOMON N. OARVALHO, on NEW YORK, N. Y., ASSIGNOR TO HIMSELF AND JAMES M. PATTEE, 0F SAME-PLACE.

' IMPROVEMENT IN STEAM BOILERS AND SUPERHEATERS.

Specification forming part of Letters Patent No.i192.678, dated July 3, 1877; application filed February 3, 1877. Y

To all whom. it may concern:

Be it known that I, SOLOMON N. CARVALHO, of the city, county, and State of New York, have invented a new and Improved 'Steam Boiler and Superheater, of which the following is a specification:

The object of this invention is to economize fuel in the generation of steam, and to superheat the steam from the boiler in a separate and independent steam-dome, so as to prevent priming, and permit pure dry steam only to i go to the cylinder of the engine. I,

The invention is further intended to provide in the lower part of the boiler, or any other part where there'is a reduced temperature on account of the disposition of the flues, or by the entrance of the feed-water, an enlarged heating-surface that assists in and accelerates the generation of steam and the more perfect utilization of the fuel.

The invention will first be described in connection with the drawing, and then pointed out in the claims.

. The exit and return sections of the heatingpipe are connected with the boiler and arranged with weighted pressurevalves to admit the escape of the water in case of too great pressure.

In the accompanying drawing, Figure 1 represents a vertical longitudinal section Fig. 2, a top view, partly in section on line as m, Fig. 1; and Fig. 3 a vertical transversesection on line y 3 Fig. 1.

Similar letters of reference indicate corresponding parts.

A represents a locomotive, marine, or other boiler; B, a hollow water-back or loose reservoir, placed in the combustion-chamber of the boiler; and O a water-conducting pipe that leaves the highest point of the water-back at the side of the boiler, and enters from the outside of the boiler into a separate steamdome, D, that is connected by a pipe and check-valve with the main steam-dome. The

heating water-pipe C is arranged in the shape of a serpentine or other coil in the separate steam-dome, and conducted then through the shell of the boiler.

.The steam in the steam-domeD is superheated and made drier, being brought by the heat of the pipe 0 to greater pressure and elasticity than the steam in boiler, so as to be used with greater effect in the cylinders of the engine, to which the steam-dome D is connected by suitable pipes. From the superheater the pipe 0 runs longitudinally through theboiler to the back of the same, then down along'the same, entering the boiler at the bottom or lowermost part, which is usually the coldest part, on account of the insufficient passage of the fire-gases through the lower flues.

By removing the lower dues and arranging the heating-pipeO in a serpentine coil at the lowermost part, as shown in Fig. 2, the heat of the water driven through the continuous pipe 0 is radiated or imparted to the water of the boiler so as to heat up that part which has hitherto received an insufficient quantity of heat. The water-pipe O is then conducted to the outside of the boiler, and returned along the bottom of the same to the lowermost part of the water-back or reservoir, forming thus a continuous hot-water circulation for the double purpose of superheating the steam in the supplementary dome and of raising the temperature of the water at the bottom or coldest part of the boiler.

For marine or other boilers the serpentine coil is arranged at such place or places where the water is not sufficiently heated on account of the disposition of the draft-fines or other causes.

The continuous water-pipe G is connected at a point before it enters the superheatingdome by a short pipe, E. With the interior of the boiler, pipe E having a weighted and automatically-working safety-valve to allow the water from the waterback to discharge itself into the boiler proper, when the temperature of the water in water-back, and, consequently, the pressure, become higher than required.

A similar pipe-connection, E, and safetyvalve, allows the water from the lowermost.

I without the use of additional fuel.

be conveyed directly into the "lowermost part of the boiler, belowthe flues,when it is desired to dispense with the superheating-dome by connecting the highest part of the waterback with the continuous circulating-pipe at the lowermost part of the'boiler and back to bottom of water-back, so that the coolest part of the boiler is heated up by means of the hot test water from the water-back, and thereby an economical and effective arrangement of utilizing the heat of the fuel obtained and the generation of steam in the boiler accelerated Water can be raised, in a metallic vessel exposed to the direct heat of a fire, to atemperature whose-height can only be limited by the vessels power ofiresistanc'e, itsown expansion being-resisted byapressure that preventsit from-being converted into steam. Steam-having a pressure of thirty five pounds to the square inch marks 260 on- Fahrenheit s thermometer, while water having the same pressurelnark-s 320. Hence waterat a'hi-gh heat may 'beemployed with facility to superheatsteam. v

In order to prevent the circulating=pipes from-becoming too1-hot,-I use-avalve weighted to'liftat a given pressure, thus mixing the water-in boiler'andthat in pipes to producer mixture at the desired temperature.

The water-backisexposed on all sidesdi rectly to the fire, contains one-tenththe-heatingsurface of boiler, and is provided with onehundredth the quantity of water. Of

course-theproportions may be varied, but the effect is the-same. In the-former instance, when the steam in boiler indicates-300 the, water in-back will show about 400. Hence the steam in passing to cylinder over this hot-i ter region or hot-water coil'mu'st 'be"superheated. '-Ihe' \vater circulates'with l g'r'eatv-elocity, giving out its heat to steam in dome and water at bottom of boiler, and returns at a reduced temperature to theback, the decrease of heat being madeup by the continuous supply from fire.

The automatic valve is merely intendedfor admitting water iii-to the'pipes ino'rder to prevent the steam from becoming too much superheated.

Having thus described myinventiom-I claim as new and desire to secure by Letters Patermost part back to the bottom :part of the water-back, substantially as specified.

'3.-T he combination, with the two domesshown and described, of the circulating water pipe 0- of the "water back, by short -pipeconnections E E, and safety-valves with 'the boiler, substantially as'described. SOLOMON N. GARVA-LHO.

Witnesses];

PAUL GOEPEL, O. SEDGWICK. 

